ip bandwidth-percent eigrp [as] [pct]
Configures the percentage of interface bandwidth that EIGRP can use for a specific autonomous system, limiting EIGRP traffic to prevent link saturation.
ip bandwidth-percent eigrp [as] [pct]When to Use This Command
- Limiting EIGRP bandwidth on a low-speed WAN link to avoid congestion with user traffic
- Controlling EIGRP overhead on a multi-access interface where multiple EIGRP processes run
- Preventing EIGRP from overwhelming a backup link during convergence events
- Adjusting bandwidth usage on a tunnel interface to match underlying physical constraints
Command Examples
Limit EIGRP AS 100 to 50% of interface bandwidth
ip bandwidth-percent eigrp 100 50R1(config-if)# ip bandwidth-percent eigrp 100 50
R1(config-if)# end
R1# show ip eigrp 100 interfaces
EIGRP-IPv4 Interfaces for AS(100)
Xmit Queue Mean Pacing Time Multicast Pending
Interface Peers Un/Reliable SRTT Un/Reliable Flow Timer Routes
Gi0/0 1 0/0 12 0/0 50 0
Bandwidth percent: 50
The command sets EIGRP AS 100 to use at most 50% of the interface bandwidth. The 'show ip eigrp interfaces' output confirms the setting under the interface line: 'Bandwidth percent: 50'.
Verify bandwidth percent on a serial link
show ip eigrp 100 interfaces serial 0/0/0EIGRP-IPv4 Interfaces for AS(100)
Xmit Queue Mean Pacing Time Multicast Pending
Interface Peers Un/Reliable SRTT Un/Reliable Flow Timer Routes
Se0/0/0 2 0/0 8 0/0 45 0
Bandwidth percent: 75
The output shows that on Serial0/0/0, EIGRP AS 100 is using 75% of the interface bandwidth. The 'Bandwidth percent' field indicates the configured limit.
Understanding the Output
The 'show ip eigrp interfaces' command displays per-interface EIGRP details. The 'Bandwidth percent' line shows the configured percentage of interface bandwidth that EIGRP may use. A value of 100 means full bandwidth, while lower values restrict EIGRP traffic. If not configured, the default is 50% for low-speed interfaces (<= 1.544 Mbps) and 100% for others. Watch for values that are too low, causing EIGRP packet drops and neighbor flapping, or too high, starving other traffic. The 'Xmit Queue' and 'Mean SRTT' fields help assess congestion; high queues or SRTT may indicate bandwidth saturation.
CCNA Exam Tips
Remember the default bandwidth percent: 50% for links <= 1.544 Mbps, 100% for faster links
The command is configured under interface configuration mode, not router eigrp mode
EIGRP uses bandwidth percent to throttle hello and update packets; setting too low can cause neighbor loss
On serial interfaces with low bandwidth, always verify the bandwidth command is set correctly before adjusting percent
Common Mistakes
Forgetting to set the interface bandwidth with 'bandwidth' command before adjusting percent, leading to incorrect calculations
Applying the command to the wrong EIGRP AS number, causing no effect on the intended process
Setting the percent too low (e.g., 1%) causing EIGRP neighbor relationships to fail due to packet drops
Related Commands
bandwidth [kbps]
Sets the bandwidth value (in kbps) on an interface for routing protocol metric calculations and QoS, overriding the default detected bandwidth.
show ip eigrp interfaces
Displays detailed information about interfaces on which EIGRP is enabled, including neighbor status, pending routes, and interface statistics, used to verify EIGRP adjacency and interface participation.
Practice for the CCNA 200-301
Test your knowledge with hundreds of CCNA practice questions covering all exam domains.
Practice CCNA Questions